The present invention relates to a method and apparatus for obtaining energy, particularly electrical energy, from a flowing stream such as a river, tidal basin or the like.
Many types of apparatus have been devised to convert the energy of a flowing stream of water into useable mechanical energy or electricity.
U.S. Pat. No. 904,892 to Pattosien discloses a “stream power electric float” which may be anchored in a stream so that the water flows beneath it. Two giant paddle wheels, mounted for rotation on the float, are driven by the flowing stream beneath the float. These paddle wheels are coupled by drive belts to an electric generator.
One advantage of this device is that it may be towed by a tugboat, motor boat or the like to a desired location, adjacent to where electrical power may be needed. A disadvantage is that the flowing stream may easily divert around, and thus bypass the paddles of the water wheels, limiting the amount of power that can be generated.
The U.S. Pat. No. 3,882,320 to Schmeller discloses a “tide energy conversion device” that comprises a stationary “channel”, rigidly mounted on vertical piles driven into the ocean floor, to capture the ebb and flow of ocean tides. Energy from the flow of water through the channel is converted into mechanical energy by a plurality of paddles or blades arranged on an endless chain stretched between two sprocket wheels. As tide water flows through the channel it pushes the “blades” which move the chain and, in turn, rotate the sprocket wheels. A shaft connected to one set of sprocket wheels drives an electric generator.
An advantage of this device, over that of Pattosien, is that once water enters the channel, it cannot bypass the blades. However, the width of this channel is somewhat limited and, once fixed in place, the structure cannot be moved from one location to another.
Various other floating devices for generating electrical power from moving streams of water are disclosed in the U.S. Pat. No. 3,922,012 to Herz; U.S. Pat. No. 3,986,787 to Mouton, Jr. et al.; U.S. Pat. No. 4,104,536 to Gutsfeld and French Patent No. 2,689,184 to Garstka. While these devices have the advantage of being mobile, like the “electric float” of Pattosien, they are unable to convert a significant portion of the energy of a flowing stream into mechanical or electrical energy. This is because the water in the stream can elect to bypass the paddles, turbines or the like which convert the energy from one form to another.
Further devices for converting the energy of moving water into mechanical and/or electrical energy, are disclosed in the U.S. Pat. Nos. 4,384,212; 4,412,417; 4,443,708; 4,465,941 and 4,717,832. All of these devices are rigid structures, however, and are not designed to be moved from place to place.